This application is based on Japanese Patent Application Nos. 11-236783 (1999) filed Aug. 24, 1999 and 11-236994 filed Aug. 24, 1999, the contents of which are incorporated hereinto by reference.
1. Field of the Invention
The present invention relates to a liquid ejection print head, a printing apparatus provided with the same and a method for producing a liquid ejection print head. The present invention is applicable not only to generally used printers but also to copiers, facsimile recorders with a communication system, word processors with a printing unit, or the like. Further, it relates to industrial printing apparatuses combined with various processing devices in a composite manner.
2. Description of the Related Art
An ink jet type printing apparatus has been put into practice, wherein the printing operation is carried out on a printing surface of printing medium. In general, the ink jet type printing apparatus is provided with an ink cartridge having a print head for ejecting ink to the printing surface of the printing medium, for example, as shown in FIGS. 22 and 23.
As shown in FIGS. 22 and 23, the ink cartridge consists of ink tanks 4Y, 4M and 4C for storing predetermined color ink, for example, yellow ink, magenta ink and cyan ink, respectively, a tank holder 2 for accommodating the ink tanks 4Y, 4M and 4C, a print element substrate 10 disposed on the bottom of the tank holder 2, for ejecting ink from the respective ink tanks 4Y to 4C through a plurality of ejecting openings, and a flexible wiring board 8 electrically connected to the print element substrate 10, for supplying a group of control signals to the print element substrate 10.
The print element substrate 10 consists of substrates 10C, 10M and 10Y for ejecting respective colored inks. Since the substrates 10C, 10M and 10Y are of the same structure to each other, the explanation will be made solely on the substrate 10M, while eliminating that of the other substrates.
For example, as shown in FIG. 21 in an enlarged manner, the substrate 10M is formed of silicon as a thin plate and has a group of ink ejection openings 10a arranged in one direction in a zigzag manner. In each of ink flow passages communicating with the respective ink ejection opening is provided a heater used as an electrothermal transducer. Also, a group of electrodes 10e are formed along opposite short edges thereof, for transmitting the supplied control signals to the respective heater via a conductor layer not shown. On the back surface of the substrate 10M is formed an elongate recess 10b in correspondence to the group of ink ejection openings 10a. 
On a bulged portion in the bottom of the tank holder 2 made of resinous material, a frame member 12 is disposed having an opening at a center thereof. In the opening of the frame member 12, a support member 14 is arranged. The support member 14 serves for dissipating heat generated when the print element substrate 10 is driven and serves for making the substrate to be mutually parallel to a surface on which the substrates 10Y to 10C are arranged. Since the frame member 12 is fixedly adhered to the support member 14, it functions as a heat dissipation member similar to the support member 14. The support member 14 and the frame member 12 are made, for example, of silicon or alumina which can be machined to have a flatness at a relatively high degree equal to that of material for the print element substrate 10 and are excellent in heat dissipation. The support member 14 has three ink supply openings 14a arranged in a central area at a predetermined interval, for allowing ink from the respective ink tanks to pass therethrough, and is fixedly adhered to the tank holder 2. As an adhesive, silicon-modified epoxy type adhesive is favorably used, which is ink-resistant to be usable as a sealant and has elasticity capable of compensating for the difference in linear thermal expansion coefficient between different kinds of material; for example, between alumina and resinous material.
At each the opposite ends of the bulged portion on the bottom of the tank holder 2 used as a holder member, a recess 2A is formed. The respective recess 2A is defined by four flat faces encircling the same. One of these four faces is a reference surface 2RS formed in the moving direction of the tank holder 2 accompanied with the ink tanks 4Y to 4C, that is, in the direction of arrow S shown in FIG. 21. The reference surface 2RS of the recess 2A engages with an engagement section 16K of a carriage member 16 described later, respectively.
Further, as shown in FIG. 22, on the frame member 12, the flexible wiring board 8 electrically connected to the group of electrodes 10e of the substrates 10C to 10Y in the print element substrate 10 is disposed. The flexible wiring board 8 has an opening at a position corresponding to the print element substrate 10.
The tank holder 2 as shown in a phantom line in FIG. 23, accommodating the ink tanks 4Y to 4C therein, is inserted into the carriage member 16 in the direction of the arrow so that it is mounted to a mounting portion within the carriage member 16 provided in the printing apparatus as shown in a solid line.
The carriage member 16 is movably held by a guide shaft GS which slidably engages into a through-hole 16b of a proximal end of the carriage member 16. Also, on the bottom of the carriage member 16, an opening 16a is formed to communicate with the mounting portion. Further, at the peripheral position of the opening 16a, an engagement portion 16K is provided opposite thereto, having a surface to be engaged with the reference surface 2RS of the above-mentioned recess 2A of the tank holder 2. The engagement portion 16K extends in the direction of the arrow S of FIG. 23, that is, in the moving direction of the carriage member 16, toward the interior of the opening 16a. 
It is necessary that the above-mentioned group of ink ejection openings 10a of the print element substrate 10 are arranged at a predetermined angle relative to the direction of the arrow S shown in FIGS. 21 and 23, for example, generally vertical thereto for the purpose of forming pixels at predetermined positions on the print surface of the printing medium as moving in the direction of the arrow S,
Accordingly, when the print element substrate 10 is located and fixed at a predetermined position on the tank holder 2, the print element substrate 10 is first positioned on the support member 14 within the opening of the frame member 12 so that the direction of the group of ink ejection openings 10a in the respective substrates 10Y to 10C are generally vertical to the reference surface 2RS, and then fixed with an adhesive. The adhesive may be, for example, an ink-resistant epoxy type heat-hardening adhesive also usable as a sealant. Thus, the print element substrate 10 is fixed on the tank holder 2 so that the group of ink ejection openings 10a thereof extend generally vertical to the reference surface 2RS.
Then, when the group of ink ejection openings 10a of the print element substrate 10 on the tank holder 2 are located at predetermined positions of the mounting portion of the carriage member, as shown in FIG. 23, the tank holder 2 is inserted into the interior of the mounting portion so that the reference surface 2RS in the recess 2A abuts to the engagement surface of the engagement portion 16K, whereby the group of ink ejection openings 10a of the attached print element substrate 10 are automatically positioned in the direction generally vertical to the direction of the arrow S.
However, as described above, the positioning of the print element substrate 10 in relation to the support member 14 in the tank holder 2 and the indirect positioning of the print element substrate 10 in relation to the carriage member 16 via the tank holder 2 are carried out based on the reference surfaces different from each other, resulting in the accumulation of positioning errors of the print element substrate 10 in relation to the carriage member 16. Accordingly, there is a risk in that the positioning accuracy of the print element substrate 10 may be degraded.
A main object of the present invention is to provide a liquid ejection type print head, a printing apparatus provided with the same, and a method for producing a liquid ejection type print head, capable of improving the positioning accuracy of the print element substrate in relation to a carriage member with simple mechanics.
To achieve the above-mentioned object, the liquid ejection type print head according to the present invention comprising, a plurality of print element substrates, each having print elements for ejecting liquid, a support member for supporting the print element substrates and a holder secured to the support member and having a section for positioning the holder in relation to a carriage movable together with the print element substrates and the support member; the liquid ejection type print head supplying the liquid to the print element substrates via the holder and the support member, wherein the section for positioning the holder in relation to the carriage is also used as a section for positioning the support member onto the holder.
Also, the printing apparatus according to the present invention comprising, a liquid ejection type print head for carrying out the printing operation by ejecting liquid and a carriage member for transporting the liquid ejection type print head while carrying the same thereon, wherein the liquid ejection type print head is provided with a plurality of print element substrates, each having print elements for ejecting liquid, a support member for supporting the print element substrates and a holder secured to the support member and having a section for positioning the holder onto a carriage movable together with the print element substrates and the support member, and the section for positioning the holder in relation to the carriage is also used as a section for positioning the support member onto the holder.
Further, the method for producing a liquid ejection type print head comprising the steps of, positioning a first print element substrate to a surface to be adhered therewith on the support member having a protrusion defining a positioning section, the first printing element substrate having print elements for ejecting liquid and a plurality of alignment marks for a positioning operation, while using a predetermined relative position of the respective alignment mark as a reference in relation to the protrusion, and positioning a second print element substrate to a surface to be adhered therewith, the second print element substrate being disposed adjacent to the first print element substrate and having a plurality of alignment marks for a positioning operation, while using a predetermined relative position of the respective alignment mark as a reference in relation to the alignment mark of the first print element substrate.
Since the present invention is provided with a basic configuration so that the section for positioning the holder in relation to the carriage is also used as a section for positioning the support member onto the holder, it is possible to improve the positioning accuracy of the print element substrate in relation to the carriage member by simple structure.
The above and other objects, effects, features, and advantages of the present invention will become more apparent from the following description of embodiments thereof taken in conjunction with the accompanying drawings.